Mesh Smoothing My Model
If you want to smooth out the whole mesh you can do it by clicking on the mesh, going into the modifiers tab, adding a Subsurface modifier and increase it's value from 1.

On the other hand if you only want to make a certain area smoother I know a couple of other options:

1) In object mode select the mesh, go into Edit Mode, click 2 to use edge selection, select the edges than you want to smooth, press CTRL+B to apply a bevel to them.

2)In object mode select the mesh, go into Edit Mode, press 3 to enable face selection, select the faces you want to smooth, press W to bring up the Specials tab, select subdivide, press 1 to enable vertex selection, press W again and click smooth.

Of these 2 options it's probably best to use the first one to keep better topology.